Reanalysis and satellite data indicate a decreasing precipitation area in recent decades, affecting local water resources and precipitation intensities. We have used CMIP6 simulations to test the hypothesis of a shrinking precipitation area in a warming climate. Our analyses reveal that SSP5-8.5 projections show a robust decrease in the precipitation area between 50 °S and 50 °N, and globally in 75% of the simulations. The new findings support the observed relationship, although to a lesser extent than earlier found in reanalysis and satellite data. We find a poleward shift of precipitation, increasing the daily precipitation area in the Arctic from 18% to 28%. At lower latitudes the precipitation area is reduced due to a decreasing occurrence of precipitation. These changes are related to the expansion of low relative humidity zones in the lower-to-mid troposphere, specifically at the poleward edges of the subtropics.

再分析和卫星数据表明，近几十年来降水面积不断减少，影响了当地的水资源和降水强度。我们使用 CMIP6 模拟来检验气候变暖时降水面积缩小的假设。我们的分析表明，SSP5-8.5 预测显示，南纬 50° 至北纬 50° 之间的降水面积大幅减少，全球 75% 的模拟均出现这种情况。新的发现支持了观察到的关系，尽管程度比之前在再分析和卫星数据中发现的要小。我们发现降水量向极地移动，北极日降水面积从 18% 增加到 28%。在低纬度地区，由于降水量减少，降水面积减少。这些变化与对流层中低相对湿度区的扩张有关，特别是在亚热带的极地边缘。